Former king of Cambodia (1941 – 2004), also known as Prince Sihanouk. He was studying in a boarding school in Saigon (Ho-Chi-Minh ville) when, against all odds, the French Vichy administration decided that he should ascend the throne instead of his maternal uncle after his grandfather King Monivong passed away, on 22 April 1941. It is assumed that he was chosen because he seemed shy and docile. He was coronated in September 1941. On 9 November 1953, he secured Cambodia’s independence from France. He abdicated on 22 March 1955 in favour of his father and became prime minister. Following his father’s death in 1960, Sihanouk won general election as head of state, but received the title of Prince rather than King. In 1963, he made a change in the constitution that made him head of state for life. While he was not officially King, he had created a constitutional office for himself that was exactly equal to that of the former Kingship.
He was overthrown by a US-backed military coup on 18 March 1970. He set up a government in exile in Beijing and launched a radio appeal to the Cambodian people to resist the authors of the coup. He was followed by a large number of his compatriots, including the Khmer Rouges.
In April 1976, the Khmer Rouges defeated the Americans and turned Cambodia into a Marxist-Leninist state. Prince Sihanouk resigned shortly afterwards and was placed under house arrest. During their rule, the Khmer Rouges slaughtered numerous members of Prince Sihanouk’s family, including several children and grand-children. According to experts specialised in Cambodian Affairs, particularly former French Ambassador Charles Malo, the only reason why Prince Sihanouk was not executed was because Mao Tse Tung had forbidden Pol Pot to do so.
In January 1979, the Vietnamese army invaded Cambodia, and China sent a plane to bring Prince Sihanouk back to Beijing. He advocated the cause of an independent Cambodia and called for UN-supervised free elections. In 1982, under the pressure of the US, of China, and of the ASEAN countries, he formed a tripartite coalition government which included Son Sann (supported by the US) and the Khmer Rouges (supported by China).
After the Paris Agreements was signed 23 October 1991, the United Nations sent its Blue Helmets to Cambodia to organise the elections. Prince Sihanouk returned to Cambodia and became the President of the Supreme National Council, a government comprising all four belligerents. In 1993, his party won a landslide victory. The newly-elected Parliament restored the monarchy, and crowned him king. On 7 October 2004, he abdicated in favour of his son Prince Sihamoni.
He died on 15 October 2012 around 1.21 am in Beijing, from heart failure, after long series of illnesses which included Lymphome-B cancer.

Link to Wikipedia biography